Wood and its properties = Древесина и ее свойства. Учебное пособие

needles. Most softwoods also bear scaly cones (inside which seeds are produced) and are therefore often referred to as conifers. Included in the

softwood group in the Northern Hemisphere are the genera Pinus (pine), Picea (spruce), Larix (larch), Abies (fi r), Tsuga (hemlock), Sequoia (redwood), Taxus (yew), Taxodium (cypress), Pseudotsuga (Douglas fir), and the genera of those woods known commonly as cedars ( Juniperus, Thuja, Chamaecyparis, and Calocedrus). In contrast to softwoods, hardwoods are angiosperms that bear broad leaves (that generally change color and drop in the autumn in temperate zones) and produce seeds within acorns, pods, or other fruiting bodies. Referring again to Picture 1 , note that angiosperms are subdivided into monocotyledons and dicotyledons. Hardwood - producing species fall within the dicotyledon class. Hardwood genera in the Northern Hemisphere include Quercus (oak), Fraxinus (ash), Ulmus (elm), Acer (maple), Betula (birch), Fagus (beech), and Populus (cottonwood, aspen). Included in the monocotyledon class are palms and yuccas. Many of the roughly 2500 species of palms produce relatively large diameter fibrous stems, which are strong if left in the round condition but tend to fall apart when cut into lumber; some species of palm, however, produce stems suitable for production of local use construction “ lumber. ”Composite panels and flooring can be made from partially refined stems, and paper can be made from the fiber. Not only do hardwood and softwood

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trees differ in external appearance, but the wood formed by them also differs structurally or morphologically. The types of cells, their relative numbers, and their arrangements are different, the fundamental difference being that hardwoods contain a type of cell called a vessel element. This cell type occurs in most hardwoods but very seldom in softwoods. Hardwoods are classified as ring -or diffuse - porous, depending on the size and distribution of vessels in a cross section. Woods that form very large diameter vessels for a part of the year and smaller ones thereafter are called ring porous. Woods that form vessels of the same size throughout the year are classified as diffuse porous. All hardwoods do not, incidentally, always produce hard, dense wood. Despite the implication in the names hardwood and softwood, many softwoods produce wood that is harder and denser than wood produced by some hardwoods. Balsa wood, for example, is from a hardwood species.

[From: Shmulsky R., Jones P. D. Forest Products and wood science / R. Shmulsky, P. D. Jones. – US : Willey-Blackwell, 2011. – P. 141]

3.Write out new words and word combinations from the text and translate them into Russian.

4.Mark the sentences T (True) or (False) according to the text.

1.Woods and the trees are divided into three categories.

2.Hardwood and softwood trees are botanically and genetically quite similar.

3.Softwood trees are commonly known as evergreens.

4.In contrast to hardwoods, softwoods are angiosperms that bear broad leaves.

5.A vessel element is a type of cell, which is contained only in softwoods.

6.Many softwoods produce wood that is harder and denser than wood produced by some hardwoods.

7.According to Picture 1, angiosperms are subdivided into

monocotyledons and di-cotyledons.

8. Angiosperms are characterized by production of seeds within ovaries, whereas gym-nosperms produce seeds that lack a covering layer.

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INSECTS

1. Read, translate and state to what parts of speech the following words belong.

Infestation, species, ant, termite, timber, shelter, powder, preservative, carpenter, destruction, damage, moisture, slab, plywood, particleboard, hazard, firewood, reinfestation, installation.

2. Read and translate the text into Russian.

Wood products in use throughout the world are subject to infestation by a wide variety of termites and beetles and by a few species of ants and bees. Some insects, particularly termites and wood - destroying beetles, cause great financial loss and are of concern in wide areas of North America. A great number of other insects are important in specific regions of the world because of their damage to standing timber, logs, and wood products in use.

Termites (biological order Isoptera) have, by far, the greatest economic impact. Over 500,000 dwelling units in the United States receive annual treatment for termite control. Subterranean termites have been reported in every state in the United States except Alaska and are relatively rare in the tier adjacent to Canada. They are most common and represent the greatest economic problem in California, the states bordering the Gulf of Mexico, and along the Eastern Seaboard from Florida to Virginia. Also common are dry wood termites, which are limited to an area within about 160 km (100 mi) from the coast of California and from the Gulf and South Atlantic coasts, including all of Florida.

Subterranean termites live similarly to ants in colonies in the ground. Most species have three social castes: workers, reproductives, and soldiers. Termites differ from ants in that they do not have the narrow waist between the abdomen and thorax, and their two pairs of equal - size wings are connected to distinct wing stubs, which are apparent when the wings are lost.

Subterranean termites usually enter wood from the ground or through shelter tubes that they construct as a means to reach the wood. They use wood both as a shelter and to obtain cellulose, their source of food. To avoid exposure to outside environments, they live entirely within the wood once a colony is established. The exterior showed no sign of its condition until

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failure occurred. For continued subterranean termite infestation, they must maintain a reasonably high level of moisture. This moisture is often brought from the ground to their sealed colonies.

Formosan termites are significantly more aggressive than their native subterranean relatives. Their severe destruction is currently slowly radiating out from the Gulf Coast area of the United States.

Dry wood termites pose a different risk from the subterranean variety because they can enter wood above the ground directly from the air. Once they have gained entry, they can live in wood with moisture contents as low as 5 or 6 percent. Wood structures in regions subject to dry wood termite attack should be inspected regularly, all cracks and exposed wood should be caulked or painted, and vents should be screened to prevent termites from coming in contact with unpainted wood.

Wood - destroying beetles in North America include lyctid beetles (true powder - post beetles), anobiid beetles (furniture beetles), false powder - post beetles, and long - horned borers. Evidence of powder - post beetles is the presence of small exit holes which vary in diameter from about 1.5 to 5 mm depending on the species and fine flourlike powder (frass) dropped from the holes. Most in - service beetle damage is aesthetic only, caused by mature beetles exiting the wood in which they developed from eggs By kiln drying or sterilizing wood products such that the core wood temperature exceeds approximately 66 ° C (150 ° F) for 2 – 4 hours, most wood - destroying beetles can be killed. Sterilization and phytosanitization processes that kill such things as nematodes and insects are often required of wood products, including pallets that will be shipped internationally.

Carpenter ants and bees do not derive nutrition from wood. Rather, these insects excavate wood for nesting purposes. As such, it is possible for carpenter ants to excavate preservative -treated lumber. Carpenter ants favor warm damp locations such as wood framing in poorly maintained (leaky) buildings, often coexisting with some level of decay fungi. By keeping wood structures dry, carpenter ant damage is largely controlled. Carpenter bees sporadically bore holes in buildings (often roof trim) approximately 10 mm (0.4 in.) in diameter. These bees cause little more than occasional aesthetic damage.

Materials selection, building design, planning of construction details, and construction practices should be carried out with consideration for the potential severity of insect damage in the region. Protection against subterranean termites in areas of low or moderate attack can be accomplished by proper soil treatment, construction of foundations, sills,

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and floor slabs so that termites cannot reach the wood without being visually detected. A combination of soil treatment and proper construction with effective termite barriers provides adequate protection in most temperate regions. Where extreme termite hazard exists, such as tropical regions, it may be desirable to use chemically treated lumber, plywood, and particleboard throughout the structure. Many chemicals that provide protection against decay are also effective against termite attack.

Care should be taken to avoid bringing lumber or firewood infested with powder - post beetles into a wood structure or a wood storage yard as these can cause reinfestation. In regions where powder - post beetles are a serious problem, freshly cut lumber may be heat sterilized or treated with insecticides to prevent attack.

It is not uncommon for reclaimed lumber, such as historic barn boards or framing that is infested with powder - post beetle eggs to be remanufactured (stripped, sawn, planed, and/or sanded) for uses such as paneling or flooring. The lumber provides a desirable character - marked appearance for use in homes, restaurants, and retail shops. It is not so pleasant, however, when the beetles later emerge and create their exit holes, often many years after installation.

[From: Shmulsky R., Jones P. D. Forest Products and wood science / R. Shmulsky, P. D. Jones. – US : Willey-Blackwell, 2011. – P. 239]

3.Write out new words and word combinations from the text and translate them into Russian.

4.Answer the following questions using the words you’ve learned in exercise 3.

1.What damage can insects bring?

2.What kind of insects have the greatest economic impact?

3.What processes are often required of wood products to kill nematodes and insects?

4.What are the possible ways of beetles’ destruction?

5.How should constructions be carried out taking into consideration the potential severity of insect damage?

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6.What can reinfestation cause?

7.How can lumber be treated to prevent insects attack?

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SUPPLEMENT

What is the difference between a resume and a CV?

The primary differences between a resume and a curriculum vitae (CV) are length, what is included, and what each is used for. While both are used in job applications, a resume and a CV are not always interchangeable.

What is a Curriculum Vitae?

Like a resume, a curriculum vitae (CV) provides a summary of one’s experience and skills. Typically, CVs are longer than resumes - at least two or three pages.

CVs include information on one’s academic background, including teaching experience, degrees, research, awards, publications, presentations, and other achievements. CVs are thus much longer than resumes, and include more information, particularly related to academic background.

A curriculum vitae summary is a one-to-two-page, condensed version of full curriculum vitae. A CV summary is a way to quickly and concisely conveys one’s skills and qualifications. Sometimes large organizations will ask for a one-page CV summary when they expect a large pool of applicants.

What is a Resume?

A resume provides a summary of your education, work history, credentials, and other accomplishments and skills. There are also optional sections, including a resume objective and career summary statement. Resumes are the most common document requested of applicants in job applications.

A resume should be as concise as possible. Typically, a resume is one page long, although sometimes it can be as long as two pages. Often resumes include bulleted lists to keep information concise. Mainly, a resume is followed by a covering letter.

What is a 'Covering Letter'

A cover letter is a written document submitted with a job application explaining the applicant's credentials and interest in the open position. Since

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a cover letter is often one of only two documents sent to a potential employer, it is often extremely important in determining whether the applicant will obtain an interview for the position. A good cover letter complements a resume by expanding on resume items relevant to the job, and in essence, makes a sales pitch for why the applicant is the best person for the job. Career experts advise job seekers to spend time customizing each cover letter for the job being applied for, rather than using a generic letter. Although this requires extra effort, it can be very helpful in allowing an applicant to stand out above the competition.

Notice.

There are some differences between British and American English and conventions. Here are some examples of the differences for your CV/resume and covering letter. But notice, they can be used either by Americans and English.

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1. Complete the CV (Curriculim Vitae) with a heading from the list given bellow.

(CAREER HISTORY, PROFESSIONAL EXPERIENCE, KEY COMPETENCIES AND SKILLS, PREVIOUS CAREER HISTORY, ACADEMIC QUALIFICATIONS, REFERENCES)

Harry Smith

Address line 1

Address line 2

T: 0121 638 0026

M: number here

E: info@dayjob.com

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MECHANICAL ENGINEER - Company name February 20015 - present

Involved in the examination, development as well as testing of mechanical equipment and tools. Responsible for providing engineering support for workshop activities to ensure that components and equipment is maintained and refurbished correctly.

MAINTENANCE ENGINEER – company name March 2005 – February 20015

Giving technical maintenance support to on site activities and ensuring that the correct components and procedures are followed to ensure quality control. Provide Mechanical Engineering expertise and technical advice to other members of staff.

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Experience of using Computer Aided Design Systems and related software.

Have previously worked with multi-national and multi-skilled crews. Experience of designing cost-effective and practical mechanical

equipment modifications to help improve safety and reliability. Able to adhere to engineering principles and techniques.

Knowledge of considering time constraints like safety, cost and environmental issues.

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Fault location

Client liaison

Quality assurance

Testing

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Exeter University Engineering Degree 2000 - 2003

Southampton College A levels 1999 - 2000

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Available on request.

Driving license: yes

DOB: 1982

Languages: English, French

2. Match the words and definitions.

(experience, training course, working hours, self-employed, retire, resign, temporary, part-time, qualifications, contract, full-time, permanent)

a.A written legal agreement______________ .

b.The knowledge you get from doing a job__________ .

c.A series of lessons to learn to do a job___________ .

d.Working for yourself, not for a company______________ .

e.To stop working when you reach a certain age, e.g. 65_________ .

f.Left a job because you wanted to do__________ .

g.Lasting for a short time_______________(opposite) .

h.For only a part of the day or the week______________(opposite_____) .

i.Exams you`ve passed or courses you`ve done________________ .

j.The time you spend doing a job____.

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